sqrt(x*x) not improved correctly

[DerekJuba-NIST]

When using "improve" on sqrt(x*x), the returned result is x. The result should be abs(x), so the returned result has high error. The Herbie example at https://herbie.uwplse.org/ processes this correctly.

[elmisback]

Definitely a bug, thank you for reporting!

I confirmed that this is the result we are obtaining from the /alternatives endpoint, so it is a problem in Herbie. I will cross-file this with herbie-fp/herbie as an issue with that endpoint and close this issue once that issue is closed.

[zaneenders]

I started looking into this.